This invention relates to an apparatus serving the operation of an elevator, the piston of which apparatus has downstream thereof pivotally interconnected thrust members the last one of which has a slide member which is provided with a support arm with which the slide member passes through a longitudinal slot of the jacket of a linear cylinder extending in direction parallel to the path of motion of the load receiving means and to which the load receiving means are attached.
From the German patent specification No. 22 58 065, a hydraulic apparatus for the operation of an elevator is known in which the cylinder in which the piston moves at the base merges into a curvature at which the cylinder extending in a direction parallel to the path of motion of the load receiving means is provided adjacently. Such a hydraulic apparatus has, as practice has shown, a substantial disadvantage which is that upon operation of the elevator in the area of the curvature of the one cylinder there is relatively large friction therebetween and the thrust members, cylinder and thrust members thereby being subject to premature wear. In order to eliminate this trouble it has already been started to replace the individual thrust members by a strand consisting of rubber-resilient material. Such a strand, however, only has a very limited life because of the friction between strand and cylinder.
Also, an apparatus for the operation of an elevator is known wherein the pivotally interconnected thrust members have a continuous toothing on one side into which the teeth of a driving wheel engage (German Pat. No. 93,667). The thrust members are guided for reversing between a rail and a roll, but are not exposed to motional forces. In this apparatus also a relatively large friction occurs between the thrust members as well as the rail and the roll.